双取代铵氧化物(R2HNO)与双取代羟胺(R2NOH)的相互转换机制的理论研究--取代基的电负性和立体效应影响  

Theoretical Studies on the Conversion Mechanism Between Double-substituted Ammonium Oxides (R_2HNO) and Double-substituted Hydroxylamines (R_2NOH)——Electronegativity and Steric Effects of Substituents

作　　者：石国升[1] 丁益宏[1] 

机构地区：[1]吉林大学理论化学研究所,理论化学计算国家重点实验室,长春130023

出　　处：《高等学校化学学报》2009年第5期1010-1013,共4页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:20103003,20573046,20773054);吉林省杰出青年基金(批准号:20050103);新世纪优秀人才支持计划(NCET)资助

摘　　要：在B3LYP/6-311++G(d,p)水平下,对一系列双取代铵氧化物(R2HNO)与双取代羟胺(R2NOH){R=NH2,N(CH3)2,N(CH2CH3)2,N[C(CH3)3]2,OH,OCH3,OCH2CH3,OC(CH3)3}的相互转换机制进行了理论研究.研究结果表明,双取代铵氧化物R2HNO的热力学和动力学稳定性受电负性和立体效应的综合控制.其中胺基系列热力学稳定性以空间位阻的影响为主,而烷氧基系列热力学稳定性以电负性的影响为主.而两者的动力学稳定性均以电负性影响为主.At the B3LYP/6-311 ＋ ＋ G（d,p） level, we studied the conversion mechanism between the double-substituted ammonium oxides（ R2HNO） and double-substituted hydroxylamines （RENOH） with R = NH2, N（CH3）2, N（CH2CH3）2, N[C（CH3）3]2, OH, OCH3, OCHECH3 and OC（CH3）3. It was shown that the thermodynamic and kinetic stability of the double-substituted ammonium oxides R2HNO are co-controlled by the electronegativity and steric effects. Amongst, the thermodynamic stability of amino-substituted species is dominated by steric effect, whereas that of the alkoxy-substituted species is dominated by electronegatiyity. The kinetic stability of both amino- and alkoxy-substituted species is mainly influenced by eleetronegativity.

关 键 词：双取代铵氧化物 双取代羟胺 热力学稳定性 动力学稳定性 

分 类 号：O641[理学—物理化学]